Agave plants grown under trial at Ayre, North Queensland show that ethanol production is higher than from corn and more economical than from sugar cane, while surviving drought in marginal landscapes.
University of Sydney agronomist associate professor Daniel Tan says there is scope for the crop to be grown in northern NSW.
In an article published this week Prof Tan, with international and Australian colleagues, analysed the potential to produce bioethanol from the agave plant.
"This is the first comprehensive lifecycle assessment and economic analysis of bioethanol produced from a five-year agave field experiment in north Queensland," he said. "Our analysis shows a bioethanol yield of 7414 litres a hectare each year is achievable with five-year-old agave plants.
Agave uses 69 percent less water than sugarcane and 46 percent less water than corn for the same yield. For US corn ethanol, the yield was lower than agave, at 3800 litres a hectare a year.
Because Agave survives dry periods, and flourishes when monsoonal weather returns, its growing period is a long one with a harvest after three to five years.
Existing clumps of the Mexican native can be seen at disused railway stations east of the Pilliga Scrub and have survived at Gins Leap, near Boggabri, planted many years ago - perhaps as a feed stock, as the plant's biomass over five years is similar to sugar cane's successive ratoons over the same period.
A relation of aloe vera, agave contains skin and gut nourishing agents like saponins and complex carbohydrates like fructans including inulin.
"These natural product are good for your health and can be easily extracted," said Prof Tan, who says the versatile plant is a natural when it comes to production of hand sanitiser - using an ethanol base with the addition of skin moisturising additives, all from the same plant.
MSF Sugar is now growing the crop commercially on Queensland's Atherton Tablelands, where it does appear to thrive best because of the tropical conditions. Juice is turned into ethanol for use as biofuel - or hand sanitiser - while the biomass is burned to produce electricity.
Queensland trial crops grown near Rockhampton and again near Ayre recorded substantial differences with agave growing twice as fast at the northern site.
Trials were proposed for the IA Watson agricultural research station at Narrabri but never went ahead. Prof Tan says the plant should do well on summer dominant rainfall country north of Dubbo while it wouldn't do as well in the south of the state with cold, wet winters and dry summer heat.
The plant leaves behind no viable seed. why? It's pollinator lives in Central America, and so it is unlikely to become an aggressive weed.
Prof Tan believes agave has the potential to bring another income stream to marginal agricultural land, with the production of health related distillates emerging as promising ventures. Ethanol biofuel, meanwhile, rides the market on the back of crude oil and is currently in a slump.
"We need to look to create high value products," Prof Tan said. "We must get away from commodities and move into more valuable products where earnings are several times higher. To do that we need to be innovative."